Pump



Oct., 31, 1967 .,nw. mcKRsoN Erm. 313499715 PUMP Y Filed April 13, 1965 ghgetyghm )lf/6.2. 1 l' @Aff/@W Oct 31, 1967 J.w.D1cKERsoN ETAL 3,349,715

PUMP

Filed April 13, 1965 2 Sheets-Sheet 2 United States Patent Oiiice 3,349,715 Patented Oct. 31, 1967 3,349,715 PUMP John W. Dickerson, Chicago, Henry T. Dinkelliarnp,

Mount Prospect, and `lose L. Luna, Chicago, lll., as-

signors to Stewart-Warner Corporation, Chicago, lll.,

a corporation of Virginia Filed Apr. 13, 1965, Ser. No. 447,659 Claims. (Cl. 18S-50) ABSTRACT 0F THE DISCLOSURE The disclosure of this application contains a sanitary pump having a piston rod extending therefrom and connected to the extending end of an air motor piston rod with a shell encircling the extended and connected ends of the rods.

This invention relates in general to pumps and more particularly to an improved, facilely sanitizable pump construction for pumping viscous substances such as food or other substances to be maintained free of contamination.

A food pump usually comprises an elongate cylinder having a reciprocable piston for extruding the food from a pumping chamber in the cylinder to an outlet. When the piston moves in one direction, it pumps or extrudes food through the outlet, while an inlet valve for the cylinder opens to allow the intake of food into the cylinder. On operation of the pump piston in the opposite direction, the inlet valve is closed, while a valve on the pump piston opens to enable the passage of food past the pump piston for subsequent extrusion through the outlet. Several types of problems exist in this arrangement since both the inlet valve and the pump piston valve are subject to the accumulation of debris, as are any crevices or sharp radii in the pump, and all must be cleaned periodically.

In addition, the pump is usually driven by an air motor or other power source having a piston rod connected to the piston rod of the pump through a coupling assembly. The extension of the pump piston into the coupling assembly must be sealed against the passage of food particles or contamination, but at the same time provide as little impediment or resistance to the movement of the pump piston, as possible. This situation is further complicated by the different areas of the motor and pump rod adjacent their coupled position so that the forces thereon are not uniform during all portions of the pump cycle.

It is, therefore, one object of the present invention to provide an easily cleaned pump for use with food or other substances to be maintained free of contamination.

It is another object of the present invention to provide a pump intake valve assembly, which is subject to a minimum accumulation of debris and which may be easily disassembled, cleaned, and assembled.

It is still another object of the present invention to provide an improved pump piston and valve assembly which is subject to a minimum accumulation of debris and which may be easily disassembled, cleaned and reassembled.

It is still another object of the present invention to provide an improved easily assembled sealing and thrust support for the piston rod of a food pump or the like, mechanically coupled to a driving source external to said pump, for preventing the importation of impurities into said pump with the minimum restriction of the rod movement.

It is still a further object of the present invention to provide an improved arrangement for coupling a food pump or the like to an air motor.

The improved intake valve assembly is provided by simply utilizing spherically-shaped valve surfaces on the intake valve for engagement with a suitable surface of the intake port, and providing a projection on a valve which extends through the port for engagement with a spring clip retaining member external to the pump cylinder. The clip also operates as a stop when the valve is moved in one direction to open the port, While permitting quick and simple disassembly and assembly of the intake valve for cleaning, repair or replacement.

The improved piston and the valve thereon simply includes a circumferential recess on the piston connected to a number of axially extended recesses in the periphery of the pump piston, and a ring valve or doughnut. The ring valve is moved to one position on the piston to prevent passage of food through the circumferential recess and moved to another position to permit passage in response to movement of the piston in respective directions. The recesses serve as self-cleaning passageways for the food particles and enable the introduction of the radial pressure against the ring valve for sealing the space between the cylinder wall and piston against the passage of food.

Sealing the pump chamber against the entrance of contaminants or the passage of food particles therefrom while enabling the facile movement of the pump rod, is provided by utilizing a friction packing having a metal backing plate bonded thereto seated in the pump shell and coupling assembly respectively with a supporting Athrust collar preventing excessive distortion of the sealing member, while serving to guide and support the rod against side thrust.

In order to avoid the effect created by the dilferential areas at the coupling between the air motor piston rod and the pump piston, the coupling assembly is provided with an aperture arranged to relieve the pressure created on movement of the rods in a direction causing air pressure to develop against the larger diameter rod, and it also facilitates visual inspection of the interior of the coupling assembly to determine the presence of impurities.

Other objects and features of this invention Will become apparent on examination of the following specification and claims together with the drawings wherein:

FIG. l illustrates the assembly of an air motor and pump with the pump and coupling assembly shown in section;

FIG. 2 is a sectional view taken along the line 2 2 in FIG. l;

FIG. 3 illustrates the action of the pump valves on the upward stroke of the lower pump piston;

FIG. 4 illustrates the action of the pump valves on the downward stroke of the lower pump piston;

FIG. 5 is a sectional view taken along the line 5-5 in FIG. 3;

FIG. 6 is a somewhat enlarged bottom view of the foot valve assembly; and i FIG. 7 illustrates the details of the friction sealing member and backing plate assembly used at the juncture between the coupling assembly and the pump.

In FIG. l an air motor of the type described in copending application Ser. No. 447,851, filed simultaneously herewith by Dinkelkamp, is indicated generally by the reference character 10. The motor Il@l is arranged to drive a food pump 12. An air inlet 14 is provided for the motor 10 through which air under pressure is supplied for reciprocating a piston having a rod 16 extending beneath the motor l0. A throttling or needle valve i8 is connected to the exhaust outlet 20` of motor l0. The passage rthrough valve 1S is adjustable by means of adjustment handle 22 and serves to regulate the back pressure on the air motor piston to enable the air motor to operate as low as 5 or 10 cycles per second at an input air pressure of up to 125 p.s.i. and at a substantially constant rate of speed as described in the above application. This ensures a substantially constant velocity for the rod 16 despite variations in load thereon such as caused by the springs controlling the valve for reciprocating the motor piston.

The rod 16 has a plug 24, which engages a socket 26 o-f an upper piston 27, extending from the upper end of a rod 28 in the pump 12. The upper piston 27 is larger in diameter than rod 16 and extends through a coupling assembly 30 between the motor 10 and pump 12.

The coupling assembly 30 comprises a cylindrical shell 32 having ferrules 34 and 36 at opposite ends for engagement against similar ferrules 38 and 40 on the lower end of the air motor and the upper end of the pump respectively. The ferrules 34 and 38 are detachably engaged by a conventional quick-connect clamp 42, and the ferrules 36 and 40 yare detachably engaged by a quick-Connect clamp 44.

The ferrule 40 has an annular recess 46 with a diameter approximately 2.160 in its upper surface and a packing or sealing member 48 is seated therein, as best seen in FIG. 7. The recess 46 is somewhat deepened as its diameter increases to provide a high unit loading static seal at the narrow opening 49 of the recess 46. This serves to prevent leakage between member 48 and ferrule 40.

The member 48 has a cylindrical opening S0 of approximately 1.250 through which the piston 27 passes. A depending annular ange 52 is provided on the packing 48. Flange 52 has a lip 54 thereon projecting inwardly at about 11 and describing a minimum diameter of about 1.217. The piston 27, which is approximately 1.241" in diameter, is therefore sealed against the passage of particles in either direction past the lip 54.

An annular stainless steel backing plate 56, approximately .031 thick and having a maximum diameter of 2.245", is bonded to the upper surface of packing 48, which has a somewhat smaller unexpanded diameter. The plate 56 is seated between an upstanding annular projection 58 on the packing 48, and a guide recess 60 in the lower surface of ferrule 36. This aids in the assembly and alignment of the sealing member 48 and the ferrules 36 and 40.

A hubbed nylon thrust bushing or guide 62 is also provided for the piston 27. Bushing 62 is seated on the backing plate 56 and held in position by a projecting lip 64 on the shell 30. It will be appreciated that packing 48 is subject to distortion as piston 27 moves relative thereto, and that bushing 62 serves to confine the packing and minimize the distortion.

When the piston 27 is reciprocated through the coupling assembly, the larger cross-sectioned area of piston 27 with respect to rod 16 causes an undesirable load to be generated on the air motor 10, as a result of difference in area of the rod 16 and piston 27. This force is reflected in a change in air pressure in the coupling assembly 30, which is relieved through an opening 66 in the shell 32. The opening 66, of approximately .31 diameter, also enables facile inspection of the interior of coupling assembly 30 for the purpose of ascertaining the presence of either food leakage from the pump 12 or the presence of impurities or contaminants.

The pump 12 comprises a generally cylindrical shell or cylinder 68, preferably of stainless steel, having a port 70 adjacent its lower end through which food is received. An exit or outlet 72 is provided adjacent the upper end of the shell 68 through which food is extruded for dispensation to a series of containers, for example, which may be moved past the outlet in sequence.

The piston 1'0d 28 extends into the shell 68 and is provided with an enlarged integrally formed piston 74 at its lower end. The piston 74 divides the interior of the shell 68 into a chamber 76 between the piston and the outlet 4 72 and a chamber 78 between the piston 74 and the inlet port 70.

The piston 74 comprises a crowned lower Bange or head of approximately 1.56 diameter which is somewhat smaller than the interior wall lof shell 68 to dene a passageway 82. Circumferential recess 84, whose wall diameter approximates .69, just above head 80, serves to communicate passageway 82 with a series of axial or longitudinal passageways 86.

Passageways 86 are approximately .69 long and are arranged at angles of 90, for example, to each other in the periphery of the piston 74. The minimum wall diameter of passageway 86 approaches 1.23". The passageways 86 extend through a flange or stop structure 88 of the same diameter as flange 80, at the upper end of piston 74. The passageways 86 thus serve to communicate food or iluid, indicated at 89, from the lower chamber 78 below the piston 74, through passageway 82 and recess 84 to the upper chamber 76 above the piston 74.

An annular or ring sealing valve 90 of rubber, having an external crowned diameter of 1.810, is slipped over the flange 80 and seats between the two flanges 80 and 88. The ring valve 90 has an inner diameter of 1.25 and is adapted to encircle the piston having a diameter of 1.23 for sliding engagement therewith between the two flange structures 80 and 88 which serve as stops for the ring. The `ring thus seals the space between the piston and the wall of shell 68 which is approximately 1.765 in diameter, and when in abutment with ange 80 also seals the recess 84 to prevent passage of any food or uid from the upper chamber 76 to the lower chamber 78.

The lower port 70 is closed by an inlet or foot valve 91, preferably of stainless steel. Valve 91 has sphericallyshaped surfaces, for example, of .75 lradius for engaging surfaces of a valve seat 92. The valve seat surfaces are inclined at approximately 40 from the vertical axis of the port and when the spherical surfaces are engaged therewith, the port is closed. The upper surface of valve 91 is also spherically shaped with a radius of substantially .75".

An elongated projection or protrusion 94 of approximately .5" diameter depends from the valve 91 through the port 70. A peripheral recess 96 is provided in the elongate protrusion 94 and this recess is engaged by a stainless steel spring clip or retainer 98. The clip 98 passes through a slot 100 between a pair of legs 102 and 104 spaced apart by 1.38 and depending from the lower end of the pump shell 68.

The spring clip 98 is generally U-shaped with opposite legs 105 and 106 each having a respective inwardly spaced leg 108 and 110 thereon. Legs 108 and 110 extend toward the back leg of the U and each terminates in a respective arcuate portion 112 and 114. The arcuate portions 112 and 114 are seated in the recess 96 which is then located approximately in the center of the Clip. Portions 112 and 114 therefore encircle the protrusion 94 along a diameter of approximately .375. The upper and lower walls of the recess 96 serve to restrain the clip from axial movement with respect to the valve 91. The clip 98 then serves to retain the valve 91 in proper relationship to the port 70 and acts as a stop on upward movement of the valve 91 so that the valve 91 does not become irretrievably disengaged from the port.

To illustrate the operation of the pump 12, force applied by rod 16 of the air motor in a downward direction against piston 27 causes rod 28 to move downwardly as indicated in FIG. 4. The ring valve 90 is momentarily restrained relative to the piston 74 due to the fluid pressure in passageway 82 and the friction between valve 90 and the wall of shell 68. When the ange 88 encounters the ring 90, the ring valve is moved down also. The passageway 84 and the recesses 86 are thus open and pressure exerted on the fluid 89 in the lower chamber 78 causes the fluid to ow into the upper chamber 76 and forces the foot valve 91 to close port 70. The piston 27 extrudes fluid in the upper chamber through outlet 72 during the downward movement of rod 28.

Since the recesses or passageways in the piston 74 have generous radii and since no retaining surfaces hinder the movement of the fluid from removing any debris left from the previous cycle, the passageways and recesses are effectively cleaned during each downward stroke. It will be noted that the ring Valve 90 seats against the lower'side of flange 88 to prevent fluid from lodging against the lower side of the flange and also extrudes any fluid lodging against the lower side of the flange together with any fluid that may have previously lodged there.

On the upward stroke, the pistons 27 and 74 are moved, as indicated by the upwardly facing arrow in FIG. 3; however, the ring valve 90 now is positioned abutting flange 80 to close the passageway 84. Radial pressure is now exerted against the ring valve 90 due to the fluid pressure in passageway 86 so that it seals the wall of the shell 68 against fluid passage. The fluid in upper chamber 76 is now extruded through the outlet 72 by piston 74 and ring 90.

Simultaneously the relief of pressure in the lower chamber 78 enables the foot valve 91 to move upwardly and open port 70 so that additional fluid enters into the lower chamber 78. The clip 98, of course, serves to limit movement of the foot valve 91 when it engages against the bottom wall 114 of the shell 68. Thereafter, on the return or downward stroke, the aforedescribed operation is repeated for passing fluid to chamber 76, while piston 27 serves to extrude fluid in chamber 76.

The ease of disassembly and assembly of the pump 12 and coupling assembly 30 for cleaning or repair is believed obvious from the foregoing. It will be noted, however, that disassembly requires only a few simple operations. The quick-connect clamps 42 and 44 are operated to their disconnect position and plug 24 is disengaged from socket 26 to disengage the pump 12 and assembly 30 from the air motor 10 and from each other. The shell 32, guide 62 together with plate 56, and seal 48 are disassembled in an obvious manner. The piston 27, rod 28 and piston 74 simply are extracted from shell 68. The ring valve 90 is then expanded for passage over flange 80 to separate it from piston 74.

Pressure is applied to clip 98 in a direction for moving legs 108 and 110 past protrusion 94 and the clip is extracted through slot 100. The valve 91 is then extracted from the shell 68.

The parts may now be easily cleaned, repaired or replaced and the ring valve 90 thereafter re-expanded for passage over the flange 80. The foot valve 91 may be retained in the shell 68, after protrusion 94 is passed through port 7G to guide the valve by simply inserting clip 98 through the slot 100 with portions 112 and 114 engaging the recess 96. The pistons 27 and 74 and rod 28 are reassembled to the shell 68. Seal 48 is engaged on piston 27 and is seated in ferrule 40. The bonded guide 56 seats in ferrule 36 and serves to pilot or guide the coupling assembly into position whereafter clamp 44 is operated to connect the pump and coupling assembly. The seal 48 is expanded somewhat under the pressure to fill the recess 46. The assembly 30 and pump 12 are then assembled to the motor by means of the clamp 42, after plug 24 is seated in socket 26.

The foregoing constitutes a description of an improved pump whose inventive concepts are believed more fully set forth in the accompanying claims.

What is claimed is:

1. A food pump and a coupling assembly through which a piston rod of said pump is connected at one end to the end of a piston rod of an air motor having a crosssectional area different than said pump rod for driving said pump rod, the improvement comprising a pump cylinder having an inlet and outlet port, an intake Valve in said cylinder having a spherical surface for engagement with a bevelled surface at said inlet port to close said port, a spring cli-p engaging said valve external to the pump cylinder and acting as a stop on movement of said valve in one direction for retaining said valve in said pump cylinder, a piston on said pump piston rod, said piston having a circumferential recess adjacent one end of said piston connected to a pluralityl of I'axially extending recesses on the periphery of said piston for enabling the passage of fluid received through said inlet port past said piston, a ring valve engaged over said piston for sealing the space between said piston Iand the wall of said cylinder against the passage of fluid and blocking said circumferential recess when moved in one direction relative said piston, stops at opposite ends of said piston for preventing disengagement of said ring valve from said piston, a packing member seated in said pump cylinder and receiving said rod for preventing passage of any fluid either from or into said cylinder, a shell for enclosing the connected ends of said rods and having .an opening therein for relieving pressures created as a result of said dierences in area of said rods while also permitting visual inspection of the interior of said shell, and a backing plate bonded to said packing member and received in a predetermined position in said shell for aligning said shell and cylinder.

2. A sealing and coupling assembly through which the piston rod of a food pump is connected at one end to the end of a piston rod of an air motor having a cross-sectional area different than said pump rod for driving said pump rod, the improvement comprising a packing member seated in one end of said pump for sealing the connected end of said piston rod, a shell for enclosing the connected ends of said rods and having an opening therein for relieving pressures created as a result of said differences in 4area of said rods while permitting visual inspection of the interior of said shell to ascertain the presence of impurities in said shell, and a metal backing plate bonded to said packing member and seated in a predetermined position at one end of said shell for Ialigning said shell and pump.

3. In the assembly claimed in claim 2, an annular thrust collar carried by said shel-l in a predetermined position surrounding said piston rod to prevent side thrust of said pump rod and bearing against said plate to prevent distortion of said packing member.

4. A sealing assembly through which the piston rod of a food pump extends from beyond the encircling wall of said pump for connection to the piston rod of an air motor for reciprocating said pump rod, the improvement comprising an annular packing member having an annular lip depending from the internal edge of said member for peripherally engaging said rod to seal the extending end of said piston rod from said pump with said packing member subject to distortion on movement of said rod, said pump encircling wa-ll having an annular recess formed at the one end from which said pump rod extends with said recess being progressively deeper from its inner radius to its outer radius for seating one side of said annular member with the opposite side of said member lying in a plane beyond said one end, means encircling the extending end of said pump rod yand engaging said one end of said pump wall and a thrust collar seated in said means engaging said pump wall for er1- gaging the opposite side of said packing member along a circumference generally coincident with the shallower portion of said recess whereby a high static sealing load is provided on said flange adjacent the shallower portion of said recess land distortion of said packing member is prevented.

5. A combination comprising a sanitary pump having a pump piston rod encircled by a pump wall and extending beyond said pump wall, an air motor having a wall encircling an air motor piston rod extending beyond the air motor wall, a socket at the extending end of either one of said rods, a head at the extending end of the other of said rods for detachably engaging the socket on the one rod and connecting the extending piston rod ends for enabling the reciprocation of said pump rod by said motor rod, a hollow shell encircling the extending and connected ends of each of said rods and having one end in abutment with one end of said pump wall and the opposite end of said shell in abutment with one end of said air motor wall for spacing said air motor wall from said pump wall to reduce the communication of impurities therebetween, the abutting ends of said shell and said pump wall each having an annular recess formed therein in communication with the space er1- circled by the respective wall with said recesses being aligned on abutment of said one shell end with said one pump Wall end, annular alignment and sealing means engaged in said recesses and retained therein solely by connement between the walls of said recesses to define an opening for scalingly receiving said extending end of said pump rod for preventing the communication of impurities between said shell and pump with the perimeter of said opening being positioned and supported by the walls of said recesses for holding said pump rod in alignment with said air motor piston rod and said encircling pump wall, and means operable for either detachably clamping or releasing said one shell end and said one pump wall end and said opposite shell end and said one motor wall end whereby said air motor, shell and purnp are either assembled into a unitary structure with said sealing and alignment means held solely by confinement between the walls of said `recesses or said air motor,

shell and pump are disassembled from each other to separate the recessed ends of said shell and pump for permitting facile removal of said sealing and alignment means.

References Cited UNITED STATES PATENTS 336,039 2/1886 Darnell 103-173 664,898 1/1901 Salford 137--533.25 1,064,071 6/1913 Hardison et al 103-179 2,060,180 11/1936 Davis 103-50 2,067,635 1/ 1937 Harris et al. 103-50 2,130,339 9/1938 Dunkelmann 103-50 2,405,279 8/1946 Victor 277-50 2,493,152 1/1950 Malcolm 277-2 2,636,441 4/1953 Woeler 103-48 2,900,917 8/1959 Schinnerer 103-50 2,901,889 9/1959 Reed 103-229 2,986,095 5/1961 Namur 103-111 3,094,938 6/1963 Blorneke 10-3-178 FOREIGN PATENTS 1,307,772 12/1961 France.

975,469 11/ 1961 Germany.

548,653 9/1956` Italy.

DONLEY J. STOCKING, Primary Examiner.

W. L. FREEH, Assistant Examiner. 

1. A FOOD PUMP AND A COUPLING ASSEMBLY THROUGH WHICH A PISTON ROD OF SAID PUMP IS CONNECTED AT ONE END TO THE END OF A PISTON ROD OF AN AIR MOTOR HAVING A CROSSSECTIONAL AREA DIFFERENT THAN SAID PUMP ROD FOR DRIVING SAID PUMP ROD, THE IMPROVEMENT COMPRISING A PUMP CYLINDER HAVING AN INLET AND OUTLET PORT, AN INTAKE VALVE IN SAID CYLINDER HAVING A SPHERICAL SURFACE FOR ENGAGEMENT WITH A BEVELLED SURFACE AT SAID INLET PORT TO CLOSE SAID PORT, A SPRING CLIP ENGAGING SAID VALVE EXTERNAL TO THE PUMP CYLINDER AND ACTING AS A STOP ON MOVEMENT OF SAID VALVE IN ONE DIRECTION FOR RETAINING SAID VALVE IN SAID PUMP CYLINDER, A PISTON ON SAID PUMP PISTON ROD, SAID PISTON HAVING A CIRCUMFERENTIAL RECESS ADJACENT ONE END OF SAID PISTON CONNECTED TO A PLURALITY OF AXIALLY EXTENDING RECESSES ON THE PERIPHERY OF SAID PISTON FOR ENABLING THE PASSAGE OF FLUID RECEIVED THROUGH SAID INLET PORT PAST SAID PISTON, A RING VALVE ENGAGED OVER SAID PISTON FOR SEALING THE SPACE BETWEEN SAID PISTON AND THE WALL OF SAID CYLINDER AGAINST THE PASSAGE OF FLUID AND BLOCKING SAID CIRCUMFERENTIAL RECESS WHEN MOVED IN ONE DIRECTION RELATIVE SAID PISTON, STOPS AT OPPOSITE ENDS OF SAID PISTON FOR PREVENTING DISENGAGEMENT OF SAID RING VALVE FROM SAID PISTON, A PACKING MEMBER SEATED IN SAID PUMP CYLINDER AND RECEIVING SAID ROD FOR PREVENTING PASSAGE OF ANY FLUID EITHER FROM OR INTO SAID CYLINDER, A SHELL FOR ENCLOSING THE CONNECTED ENDS OF SAID RODS AND HAVING AN OPENING THEREIN FOR RELIEVING PRESSURES CREATED AS A RESULT OF SAID DIFFERENCES IN AREA OF SAID RODS WHILE PERMITTING VISUAL INSPECTION OF THE INTERIOR OF SAID SHELL, AND A BACKING PLATE BONDED TO SAID PACKING MEMBER AND RECEIVED IN A PREDETERMINED POSITION IN SAID SHELL FOR ALIGNING SAID SHELL AND CYLINDER. 